Tunable cavity resonator electron discharge device



Sept. 9, 1952 w. w; HANSEN EI'AL 2,610,307 TUNABLE CAVITY RESONATOR ELECTRON DISCHARGE DEVICE Original Filed Sept. 2, 1942 BYS/GURD E VAR/HIV v Patented Sept. 9, 1952 IUnABLE ;2,s1o,so1 I c'AvrrY RESONATOR ELECTRON DISCHARGE DEVICE r Williain- W. Hansen, Stanford University, and

. --Russel l H. Varian,

i 1 ,"Sig'ur'd' F Varian, Garden City, N. Y.,

to The'Board ofTi-ustees of The Leland Los Angeles, Calif., and

assignors Stanford Junior University, Stanford University, Calif., a legal entity of California Application September 2 which is a division ,1942, Serial No. 457,096, 1 application Serial No.

343,528, July 2, 1940. Divided and this application June 26, 1946, Serial No. 679,548

1 Claim. (Cl. 315-45) The present invention relates generally to tuning apparatus for high frequency tube structures having enclosed oscillatory circuits or cavity resonators of the type disclosed in Patent No. 2,242,275, issued May 20, 1941, in the name of Russell H. Varian, one of the present inventors. The present application is a division of our copending application Serial No. 457,096 filed September 2, v1942 which issued October 29, 1946 as,

Patent No. 2,410,063, and which in turn is a division of our Patent No. 2,311,658 issued February 23, 1943 on an application filed July 2, 1940, Serial No. 343,528.

The principal object of the present invention is to provide improved tuning means for varying the resonant frequency of a cavity resonator of such a tube structureeither locally or at some distance from the tube. According to the present invention, such tuning of a cavity resonator is effected by coupling thereto a further tunable cavity resonator by means of a length of high frequency transmission line, such as a coaxial line, and either varying the length of the line or varying the tuning of the tunable resonator, thereby altering the resonant frequency of the resonator which is to be tuned.

Other objects and advantages will become apparent from the present specification taken in connection with the single figure of the accompanying drawing, wherein the invention is embodied in concrete form.

In the drawing, the single figure represents a longitudinal view, partly in cross-section, of a cavity-resonator velocity-modulation or klystron tube to which is coupled the novel tuning apparatus of the present invention. In this figure there is shown a tube structure having a pair of cavity resonators I03, I04 carried by the inner ends of tubular members I05, I06. opposed end walls I01, I08 of resonators I03, I04 are annularly corrugated and flexible and carry a drift-space-providing tube I 09,. Resonator I04 has a dished wall I29 opposite which is a cathode I50 and modulating and/or focussing electrode I I in alignment with the resonators I03, I04. Resonator I03 has a similar wall I28 opposite which is a collector or detector structure I53. Resonators I03 and I04 are provided with coupling loops I54 connected to concentric line terminal posts I39 for coupling these resonators to external circuits, to supply or extract energy to or from the resonators, or for tuning, according to the present invention.

A suitable tuning mechanism, such as is described more in detail and claimed in parent The inner Patent No. 2,311,658, may be interposed between tube I09 and respective members I05, I06 for flexing the walls I01, I08 to tune the resonators I03, I04. Since this tuning mechanism forms no part of the present invention, it will not be described here but reference is made to the abovementioned parent patent for a more complete description thereof.

For tuning resonators I03, I04 from a remote or local point, external tuning resonators I20, I2I are used. Resonators I20, I2I are connected by respective concentric lines I22, I23 to the terminals I39 or resonators I03, I04, the loops I24 in the ends of these lines within resonators I20, I2I serving to link the resonator fields of resonators I03, I04 with those of resonators I20, I2l respectively. Tuning resonators I20, I2I are provided with suitable variable impedance means, shown as a loop I25 in resonator I20 and as a plate I26 in resonator I2 I both of which are turnable by means of knobs I21, I21. By turning these knobs, the natural frequency of oscillation or resonant frequency of resonators I20, I2I is varied, thereby effecting a variation in the resonant frequency of the connected resonators I03, I04. The length of the concentric lines I22, I23 is variable depending upon the location of the resonators I20, I 2|, relative to the tube structure itself.

Further tuning of the resonators I03, I04 may be effected by varying the length of lines I 22,

I23, as by conventional sliding joints, such as is indicated schematically with respect to line I23 by the reference numeral I50.

Since many changes could be made in the above construction and many apparently widely difierent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is: p

In combination with a high frequency electron discharge tube which includes a cavity resonator, apparatus for adjusting the resonant frequency of said resonator at a point remote from said tube, said apparatus including a second resonator at said'remote point havin continuously imperforate conductive walls which completely enclose the space within said second resonator except for a single opening which is relatively small with respect to said second resonator; a coaxial transmission line with one end coupled to said first resonator and its other end coupled to said second resonator through said opening, and UNITED STATES PATENTS means for adjusting the reactance of said. second N m Nam-e f D resonator, to thereby vary the resonant frequency 2,233,166 Hahn 25, 1941 firstreswator- T 1 2,280,824 Hansen et a1. Apr. 28, 1942 WELIAM 9- 5 2,281,935 Hansen et a1. May 5, 1942 RUSSELL IAN- :1 2,304,186 Litton De 8, 19 2 SIGURD i v a" 2,404,279 Dow July 1 1945 REFERENCES CITED 1 y 1 r OTHER REFERENCES The following referencesare of .recoid in'the m Radio Eng n rin y Terman, nd file of this patent: V published byMcGraw-Hill, copyright 1937, pp. 

